This invention relates to an improved system and method for enteric feeding in which a fluid material may be introduced into a preselected portion of the gastro-intestinal tract of a patient, the system comprising an elongated flexible tube with a device for measuring pH positioned thereon, a monitoring device capable of processing a signal indicating the pH of the area adjacent to the pH measuring device to determine the position of the tube, and fluid feed control means.
Various types of tubes and intubating methods have been developed for use in diagnosing and treating problems related to the gastro-intestinal system. Physicians have used tubes introduced orally or nasally into the esophagus and stomach as means for furnishing food or medication to these areas. For example, U.S. Pat. No. 2,230,218 to Asche describes a gastro-intestinal treatment system utilizing a duplex treatment tube with separated passageways, one communicating with the stomach and the other with the duodenum. Other examples of systems and methods relating to gastro-intestinal intubation are described in U.S. Pat. No. 3,043,309 to McCarthy and U.S. Pat. No. 4,134,405 to Smit.
Intubation procedures may also be useful for diagnostic purposes. For example, U.S. Pat. No. 3,888,237 to Mori describes a pH-measuring device used in an endoscope which may be used to measure the pH of a liquid present in a living body, such as gastric juice oozing from the inner walls of the stomach. Use of a small glass pH electrode has also been described as effective in monitoring the frequency and duration of stomach acid reflux into the esophagus. ("Flexible pH Electrode for Esophageal and Gastro-Intestinal Research", by Microelectrodes, Inc.).
While intubation systems are used in a number of ways and with a variety of apparatus, enteric feeding procedures still involve a number of problems. Positioning of the tube in the duodenum of the patient is an important part of an enteric feeding procedure. By placing the feeding portion of the tube (e.g. an area of tube containing openings which communicate with the area outside of the tube) in the duodenum, a patient may be given nourishment or medication in the form of fluid material with a much decreased hazard of regurgitation as occurs when the material is introduced into the stomach. Unfortunately the positioning of the tube is usually done with the need for X-ray or fluoroscope monitoring or by feel as accomplished by an experienced practitioner. Even if these methods are initially successful in positioning the tube in the preselected area, they are not useful for long range monitoring of the position of the portion of the tube which is in open communication with the preselected area of the gastro-intestinal tract. More particularly, if the feeding portion of the tube should slip from the duodenum back into the stomach during the process of introducing fluid material into the tube, the patient may experience a much increased danger of regurgitation which could result in asphixiation and death.
Thus it is an object of this invention to provide a system and method useful for introducing fluid material into a preselected area of the gastro-intestinal tract of a patient.
It is a further object of this invention to provide a system and method for enteric feeding in which the position of a feeding portion of a tube used in the system may be continuously determined by measuring and monitoring the pH of a body fluid.
It is another object of this invention to provide a system and method for enteric feeding in which the position of the feeding portion of the tube may be monitored without the use of X-rays.
It is yet another object of this invention to provide a system and method for enteric feeding which may include the automatic termination of feeding when a processed pH signal indicates the feeding portion of the tube is out of position.
These and other objects of the invention will become apparent from the following description of the invention.